On account of advantages such as accurate and sensitive positioning, good touch feeling, and long service life and the like, capacitive touch screens are more and more popular among manufacturers and users and are applied in many fields. The capacitive touch screens are divided into two types of self-capacitive touch screens and mutual-capacitive touch screens. Due to capability of multi-point touch, the mutual-capacitive touch screens become a mainstream and a future development trend in a capacitive touch screen market.
The mutual-capacitive touch screens are divided into two structures, i.e., an on cell type and an in cell type. In an on-cell mutual-capacitive touch screen (hereinafter referred to as on-cell touch screen), a touch component is attached to an external part of a display panel, specifically to an external part of a color filter substrate, namely On Cell; in an in-cell mutual-capacitive touch screen (also known as in-cell mutual-capacitive touch screen, hereinafter referred to as in-cell touch screen), a touch component is integrated between a color filter substrate and an array substrate, namely In Cell. The on-cell touch screen inevitably increases thickness and weight of the entire display device, thereby reducing light transmittance, which cannot meet requirement of the current development trend on a lighter and thinner display device. The in-cell touch screen has obvious advantages in reducing thickness of the display device and increasing transmittance as the touch component is integrated to an internal part of the display panel, so that a lighter and thinner display device can be achieved while realizing a touch function.
However, compared with the on-cell touch screen, the in-cell touch screen has an unsolved technical difficulty that an electrode layer located inside a display panel is closer to a touch screen electrode, which is easy to cause interference between a touch signal and a display signal, thereby leading to a lower signal to noise ratio of the in-cell touch screen.